In Hudgin U.S. Pat. No. 3,997,624, it was disclosed that high melting PE waxes can be made using an aliphatic hydrocarbon solvent, such as hexane. Although the process described in U.S. Pat. No. 3,997,624 produces a high quality wax, the method as described has a major drawback, namely that relatively large amounts of catalyst were required. Another drawback is that there must be used a volatile organic solvent.
It has also been previously proposed to polymerize ethylene in the presence of a molten petroleum wax, e.g. a crystalline or paraffin wax, Newberg U.S. Pat. No. 2,706,719.